Comparison of simple and rapid extracting methods of free-tags Mycobacterium tuberculosis protein 64 Recombinant Protein from polyacrylamide gel: Electroelution and the optimized passive elution

Purity of maltose-binding protein - Recombinant streptavidin expressed in Escherichia coli BL21 (pD861-MBP: 327892)

Nearly 95% of streptavidin which is expressed in Escherichia coli found as an inclusion body. Protein expressed in an inclusion body form requires further steps for the folding process related to its purification. Whereas the purity level of the recombinant streptavidin is very crucial mainly for the specification test in diagnostic system. In this study, we designed synthetic gene of streptavidin to be fused with maltose-binding protein (MBP) gene to enhance its solubility when expressed in E. coli BL21 (pD861-MBP: 327892) and purified using amylose resin with gradient column buffer. Based on the SDS-PAGE characterization, the majority of recombinant streptavidin was found in soluble than that of insoluble form. Recombinant streptavidin was found at its suitable size at 56.6 kDa in the soluble protein fraction with a concentration of 537.42 mg/L. The purest fraction of streptavidin recombinant was obtained at the 58^th fraction in a concentration of 0.86 mg/L with purity level of 98.77%. Compared to the initial crude protein extract, the level of purity is lower, 6.03%. In summary, the MBP purification method improves the purity level and enhances the solubility of the recombinant streptavidin.

New robustaflavone from Garcinia latissima Miq. leave and Its antibacterial activity

Isolation and determination of antibacterial compounds from plants are essential to obtain a new antibacterial as a substitute for conventional resistant antibiotics. This study aims to isolate and identify a new robustaflavone as antibacterial activity from Garcinia latissima Miq. leave. In this study, the isolation process was carried out using column chromatography followed by preparative thin layer chromatography (TLC) based on the TLC profile. The fraction D was tested for anti-bacterial Bacillus subtilis using the TLC bioautography method. The isolates obtained were then identified using 1H-NMR, 13C-NMR, distortionless enhancement by polarization transfer, heteronuclear single quantum coherence, and heteronuclear multiple bond coherence. The Activity assay of the isolate was performed using the microdilution method. A pure compound obtained the result of the separation process with eluent n-hexane: Ethyl acetate (3:2) with Rf 0.6. This spot follows the spot in the contact bioautographic result of fraction D, the spot with Rf 0.6 gives an inhibition zone. After identifying and purifying the isolate were known as Robustaflavone, this compound has activity against B. subtilis with a (minimum inhibitory concentration) value of 2500 ppm. Robustaflavone successfully isolated and identified from G. latissima leave and its antibacterial activity.